1. Field of the Invention
The present invention relates to an ultrasonic diagnostic apparatus and in particular to a three-dimensional ultrasonic diagnostic apparatus having a function to display an arbitrary cross section.
2. Description of the Related Art
Ultrasonic diagnostic apparatuses are known in which ultrasound is transmitted to/from a three-dimensional space including a target tissue to obtain three-dimensional image data and an arbitrary cross section of the target tissue is displayed based on the three-dimensional image data. For example, Japanese Patent Laid-Open Publication No. 2002-245487 discloses an ultrasonic diagnostic apparatus which displays a synthesized image of a three-dimensional image and an image of an arbitrary cross section, and, at the same time, displays a cross sectional image which is an image of the arbitrary cross section viewed from the front. This type of ultrasonic diagnostic apparatus which has a function to display an arbitrary cross section is effective in ultrasonic diagnosis of a heart.
In an ultrasonic diagnosis of a heart, for example, an ultrasonic diagnosis of a left ventricle of a heart, the diagnosing person desires a cross sectional image in which the intracardial portion of the left ventricle enlarged. For this purpose, the diagnosing person suitably moves the cutting plane while viewing a three-dimensional image and/or cross sectional image displayed on the ultrasonic diagnosis apparatus to specify an optimum cross section.
In order to specify an optimum cross section in a three-dimensional space, however, it is necessary to set translational movement of the cross section and/or rotational movement of the cross section with respect to each axis (for example, x axis, y axis, and z axis). In other words, a diagnosing person is required to repeatedly execute setting of translational movement of the cross section and/or rotational movement of the cross section with respect to each axis while viewing the three-dimensional image and/or cross sectional image displayed on the ultrasonic diagnostic apparatus. Because of this, the operation to set an optimum cross section becomes complicated and requires expertise.